Motor vehicle with automatic main clutch and automatic transmission



Oct. 28, 1941. s. BURNS A 2,260,798

MOTOR VEHICLE WITH AUTOMATIC MAIN CLUTCH AND AUTOMATIC TRANSMISSION IOriginal Filed Jan. 30, 1939 6 Sheets-Sheet l BI. BURNS Oct. 28, 1941.

MOTOR VEHICLE WITH AUTOMATIC MAIN CLUTCH AND AUTOMATIC TRANSMISSION0'riginal Filed Jan. 30, 1939 6 Sheets-Sheet 3 fine? K/ RzEHARP/S B.BURNS 2,260,798

, MOTOR VEHICLE WITH AUTOMATIC MAIN CLUTCH AND AUTOMATIC TRANSMISS IONOriginal Filed Jan. so, 1959 v 6 Sheets-Sheet 4 B. BURNS Get. 28, 1941.

MOTOR VEHICLE WITH AUTOMATIC MAIN CLUTCH AND AUTOMATIC TRANSMISSIONOriginal Filed Jan. 30, 1939 6 Sheets-Sheet 5 Mu'Sm/M? m0 fs mosne'co m5mm;

W FDR 771C HEM Abra-fiasco aavame-mo Oct. 28, 1941.

B. BURNS 2,260,798

MOTOR VEHICLE WITH AUTOMATIC MAIN CLUTCH AND AUTOMATIC TRANSMISSION'Original Filed Jan. 30, 1939 6 Sheets-Sheet 6 fave/aw: 191-6609 films;

f/AKP/J} A IAECH Has HA/ k/J at W THE HEM I Patented Oct. 28, 1941um'rso" STATE Salsbnry Corporation, Inglewood, 0.111., a cerporation ofCall! Original application January), 1939, Serial No.

ppiication 253,551. Divided and this a g 1940, Serial No. 332,404;

6 Claims. (01. 741-2165) My invention relates to motor vehicles. A motorvehicle is a vehicle driven by an engine which will preferably be of theintemal combustion type, although my invention may be used with otherforms of prime mover. A motor vehicle is ordinarily driven by oneor moredriving wheels upon which the weight of the vehicle is power mechanismincluding a clutch and a speed reduction gear for use in motorvesupported-and which are driven from the en-.

- gine through a power transmission mechanism.

l' 'ower transmission mechanisms, as used in motor vehicles to which myinvention applies, ordinarily include 'a' clutch through which the pow-'er of the engine-can be transmitted when the clutch is engaged. Such aclutch is highly desirable when the vehicle isdriven by an internalcombustion engine, since, with the clutch disengaged, the engine doesnot transmit power to the driving wheels and the engine may be startedand will rotate freely independently of the driving mechanism. of thevehicle. This driving mechanism in vehicles to which my invention may beapplied includes a speed reduction gear to which power may be appliedfrom the engine through the clutch and which in turn delivers power tothe driving wheels. through suitable mechanism.

hicles with which it is unnecessary to provide any mechanical means,such as a clutch pedal to 011-- erate the clutch or a gear shift leverto control the speed ratio of the speed reduction gear, the operation ofboth the clutch and speed reduction gear being automatically performedto suit the needs of the vehicle in actual operation.

It is an object of my invention to provide 'a light vehicle having apower transmission through which the engine, or motor, drives the reardriving wheel and which is entirely automatic in the sense that thetransmission has a main'clutch which engages and disengagesautomatically, this engagement and disengagement being affected.

and controlled automatically by an increase or decrease of engine speedabove or below a critical Such a speed reduction gear includes a drivingshaft receiving power from the engine through the clutch and a drivenshaft which delivers power to the mechanism driving the rear wheel.

The speed ratio of any such a speed reduction gear may be expressed as afraction, of which the denominator is one and the numerator is a numbercorresponding to the number p1 revolutions the driven shaft .makes asthe driving shaft is turned one revolution. The speed ratio so expressedmay be unity or more or less than unity.

In motor driven vehicles it is common to use variable ratio speedreduction gears, that is, gears by which the speed ratio may be variedmanually. In the ordinary vehicle the speed ratio may be varied from avalue of, say, three to a value of one. When the speed reduction gearhas a value of three, the vehicle is said to be in low" gear, and whenit has a value of one, it is said to be in high gear.

In thecommon types 01 automobiles having a clutch and variable ratiospeed reduction gear, it is common practice to have the operator controlthe engagement'and disengagement of the clutch throu h a clutch pedaloperated ordinarily by the left foot and to control the speed ratio ofthe speed reduction gear by a gear shift lever operated by theright-hand of the operator.

It is an object of my invention to provide a engine speed and thetransmission also includesa variable speed belt drive the ratio oftransmission of which is dependent'solely on the speed of rotation ofthe rear wheeland is hence a direct function of vehicle speed.

Various attempts have been made to devise automatic us for vehicles sothatthe operator 'of the vehicle would not have to operate a clutchpedal to connect and disconnect the motor from. the driving mechanismand operate a gear shift lever tolcontrol the ratio of engine speedto'wheel speed.-

The mechanism disclosed herein makes it possible to dispense with directmanual or pedal control of both the cluthand transmission. This itaccomplishes by making the operation of the clutch dependent solely onengine speed and the operation of the ion dependent solely onrealwheelorvehiclespeed The elimination of the necessity of manualoperation of the clutch and transmission greatly simplifies vehicleoperation and construction and makes a lightweight vehicle such as isdescribed hereinafter. Bu'cha vehicle is low in first costandoperatesatalowcost. a

,More important, it provides a vehicle that has great mobility, as theoperator is relieved of sevand operations w in driving other types ofvehicles.

To accomplish these and other desired objects I provide a V-belt onwhich may assume a low gear position in which, with the en gine runningat.a constant speed, the

sion can propel the vehicle at a slow speed or which may assume a highgear position in which, withtheenginerunning atthatspeed, thetransmissioncanpropelthevehicleatahiglgerspeed.

I also provide means by which said transmission is shifted from low gearto high gear as the speed of the vehicle is increased or from high gearto low gear as the speed of the vehicle is diminished.

The operation of this V-belt transmission is automatic at all times, itstransmission ratio being dependent on, and a function of, the speed ofthe vehicle.

To render such a transmission fully effective I also provide a mainclutch for connecting the power receiving end of said transmission tothe engine, this main clutch being inoperative so that the engine canrotate without delivering power to the transmission when the engine isrotating below a critical speed and automatically rendered operativewhen the engine is rotated at or above said speed.

The operation of this main clutch is automatic at all times, itsoperation being solely dependent on engine speed. The clutch engageswhenever the engine rotates above a critical speed and disengageswhenever the engine rotates below that speed.

These and other apparent objects I attain in a manner which will beclear from a consideration of the following description taken inconnection with the accompanying drawings, in which Fig. 1 is anelevational view of the power plant employed in a motor vehicleembodying my-invention.

Fig. 2 is an elevational view of the power plant shown in Fig. 1, takenfrom the opposite side thereof.

Fig. 3 is a cross-sectional view of the automatic power transmissionapparatus forming a part of the power plant shown in Fig. 1.

Fig. 4 is a partial cross-sectional view of the clutch mechanism shownin the idling position.

Fig. 5 is a sectional view of a portion of the apparatus of Fig. 3 takenalong the line 55 in the direction indicated by the arrows.

Fig. 6 is a sectional view of a portion of the apparatus of Fig. 3 takenalong the line 6-6 in the direction indicated by the arrows.

Fig. 7 is a sectional view of a portion of the apparatus of Fig. 3 takenalong the line 'I-| in the direction indicated by the arrows.

Fig. 8 is a partial view of the apparatus of Fig. 3 from above, asindicated by the arrow 8.

Fig. 9 is a sectional view of a portion of the apparatus of Fig. 3 takenalong the line 3-9 in the direction indicated by the arrows. I

Fig. 10 is a sectional view of a portion of the apparatus of Fig. 3taken along the line I0--|0 in the direction indicated by the arrows.

Fig. 11 is a diagrammatic illustration showing, for one adjustment ofthe apparatus, the position of the belt under idling condition.

Fig. 12 is a diagrammatic illustration showing the belt in extreme lowgear position.

Fig. 13 is a diagrammatic illustration showing the belt in the extremehigh gear position.

Fig. 14 is a diagrammatic illustration showing the belt in anintermediate position under conditions in which the vehicle is beingmoved forwardly before the engine has started.

Fig. 15 is a chart illustrating the performance characteristics of theapparatus of my invention.

Fig. 16 is a chart illustrating the performance characteristics of theapparatus of my invention.

Fig. 1'7 is a cross-sectional view of an alternative form of thecountershaft unitof my apparatus Fig. 18 is a cross-sectional view of.an alternato various types of vehicles.

tive form of a portion of the clutch and pulley unit of my apparatus. v

Fig. 19 is across-sectional view of an alternative form of a portion ofthe clutch and pulley unit of my apparatus.

, Fig. 20 is a cross-sectional view of an alternative form of a portionof the clutch and pulley unit of my apparatus.

The invention claimed herein can be applied The vehicle illustrated hasa frame having cross members 36 and 31 and vertical members 38. A powerplant 35 is supported on this frame and includes an engine 4| which iscarried on a wheel housing 40. This engine is preferably an internalcombustion engine. A wheel 42 is mounted within the housing on an axle43 adjustably supported by the frame members 36 and 31. .Associated withthe crankshaft 44 of the engine is a driving pulley 45 which drives adriven pulley 46 through a belt 41 on a countershaft 48 rotatablysupported in bearings 50, in turn supported by the wheel housing 40. Thecountershaft 48 extends in a transverse horizontal direction through thewheel housing 40 and carries a sprocket 5| on the end thereof oppositeto that with which the .driven pulley 46 is associated. The sprocket 5|is in driving relation, through a chain 53, with a sprocket 52, mountedon the axle 43 for rotation with the wheel 42.

It will be evident that the entire power plant.

35, including the driving wheel, is supported directly or indirectly bythe horizontal frame members 36 and 31. The power plant may then bemounted in the vehicle by attaching the members 36 and 3'Ito the chassisframe. As illustrated, the power plant is located at the extreme rear ofthe vehicle, the frame members 36 and 31 of the power plant unit beingattached at the rear to the frame 30 through suitable spacers 51 bybolts.58, and at the front to a cross-bracing member 3| through bracketsby bolts 6|. A cover 62 rests on the frame 30, enclosing the power plantunit 35 and servingas a support for an operator's seat 63. The cover 62is held down by thumb nuts 65 screwed on the ends of the rods 54 whichextend through the top of the cover 62. The seat is retained in positionby a spring catch 66. With this construction the power plant unit 35 isalways readily accessible and may be removed in one unit, facilitatingrepair and replacement.

The forward end of the vehicle can be pro vided with one or more pivotedwheels which support the forward end of the frame 30 and act as steeringwheels. Steering mechanism controlled by the operator may be supplied.

The construction and operation of the automatic power transmission meansof my invention will now be considered. The crankshaft 44 of the engine4| projects from a bearing boss I00 on the side of the crankcase |0| ofthe engine 4|, and carries a hub I02 and a housing I03 which arepreferably welded together. A pair of diametrically opposed fiat facesI04 milled on the extended end of the crankshaft 44 engages mating fiatsurfaces in the end of the hub I02 in such manner that the crankshaft 44and the hub I02 are rotatively keyed together. A nut I05 engages threadson the extended end of the crankshaft 44 and, acting through a washerI06 holds v the hub, I02 firmly in place on the crankshaft 44.

Freely journaled on the cylindrical outer surface of the hub I02, withsuitable end clearance, is a bushing I01 which is pressed into andcarries a tubular pulley hub I08. An inclined pulley face I I is weldedto the exterior of the pulley hub I08.

Another inclined pulley face III opposed to the pulley face H0 isadapted to slide and rotate V on the pulley hub I08 and for this purposethe pulley face III oscillate in a plane parallel to the axis of theunit 45, but to be retained against the action of centrifugal force. Theconsist of loops of wire pivotally connected at springs 5, preferablyone end to the posts I14 and at the other end con- I nected in a similarmanner to posts IIG which are riveted to a dish-shaped housing H1. Thehousing II1 is formed with a series of circumferentially spaced keys II8which engage corresponding slots I in the end of the pulley hub I08and'are held in place by a snap ring I2I engaging a groove on the pulleyhub I08. -Compression type helical coil springs I22 and I28 surround thepulley hub I08 housing H1 and the pulley. face III, thus urging thepulley face III toward the pulley face H0 at all times. It is apparentthat the pulley face III is axially movable relative to the pulley faceH0 and the housing II1, 'but'is constrained to rotate therewith byreason of the torque link springs I I5. The pulley faces H0 and III andtheir associated parts formthe driving pulley of an automatic belttransmission, this pulley being generally designated byvthe numeral 45.The diameterof this driving pulley automatically increases asthe'tension on the belt 41 decreases and decreases as the tension on thebelt increases.

Referring now to that portion of the unit 45 which functions as anautomatic clutch, it will be seen that an annular ramp I25 is spun inplace at I28 to form an integral unit with the housing I08 and thehub-I02. Shrouded within the ramp member I25 is a floating plate I21 andare compressed between the toothe pulley face I It by lugs I88 passingthrough holes in the member I81. As seen best in Fig. 6, the teeth I85are formed by shearing the innermost edge of the plate I82 radially andbending the adjacent-portions away from the line of shear into planesperpendicular to the plane of the plate I82. In this manner a .pair ofteeth is formed leaving a space between, and this opera,-

tion is repeated around the edge of the plate to form a series of suchpairs of teeth. A similar operation is used to form the pairs of teethI86 on,the outermost edge of the member I81. The teeth on the two matingmembers are so spaced that a pair-of teeth I88 fits with suitableclearance in the space left by bending out a pair of the teeth I85, allof the teeth being directed in the sagie direction. It will be evidentthat this connection-compels the plate I82 and the member I81 to rotatetogether while permitting the'plate I82 to move axially with respect Themembers I25 to I81 and associated parts form a main clutch the functionof which is to connect and disconnect the engine to the driving pulley45 of the V-belt transmission previously described.

Afterthe engine is started by means not described, the main clutch isadapted through a centrifugal clutch action to automatically connect theengine to the pulley IIO--I II to drive the vehicle when the speed ofthe engine exceeds a certain predetermined value. When the crankshaft ofthe engine is rotating, the hub I02, the housing I08, the ramp I25, andthe floating plate .I21 rotate as a unit. When the speedof rotation islow, as in idling of the engine, the parts occupy positions as shown inFig. 4. The extended annular coil spring I80 is nested within the rampI25-and rotates with the ramp. In the position shown in Fig. 4 thespring I80 exerts no axial force on either the floating plate I21 or theramp I25, permitting the plate I82 to remain stationary while the otherclutch elements rotate about it. The spring tension and total weight ofthe grommet spring are so balanced that, in the normal idling range ofthe engine,

' it will remain in the retracted position shown in which is free tomove axially relative to the ramp but is rotatively keyed thereto byfingers I28 which pass through holes in the ramp I25. Disposeda'nnularly between the floating plate I21 and the ramp I25 is acircumferentially resilient centrifugal element, preferably having theform of a grommet spring I80, and preferably consisting of a closelywound spring with its ends hooked together to form a ring and withinwhich is a similar spring I8I of smaller pitch diameter with its endsleft free. The grommet spring I80 is preferably so wound andproportioned that when in place within the ramp I25, it retracts itselfinto firm contact with the curved innermost portion of the ramp. Theramp I25 is so shaped acting upon Fig. 4, but upon increase of enginespeed appreciably above the idling range. centrifugal force the grommetspring will expand it radially to a greater circumferential length.

- As the grommet spring moves outward it is forced in the direction'ofthe floating plate 121 by the frusto-conical surface of the ramp I25,and

that it approaches the plate I21 as it proceeds outwardly from' the axisof rotation, so that enlargement of the grommet spring I80 to a largerradius results in movement of the grommet spring toward the floatingplate I21. Located between the floating plate I21 and the housing I28 is-manently attached to the concave side of the moves thefloating plateI21 into contact with the friction face I88. Continued expansion of thegrommet spring I causes the plate I82 to be moved until the frictionface I84 contacts the housing I08, when the plate I82 will tend to bedriven by frictional contact with a moving surface on either side. Theclutch in the engaged position is shown in Fig. 3.

Gentle engagement of the clutch, with slippage, thus begins at somepredetermined s'peed above the normal idling range, and increase ofengine speedabove this vaue increases the axial force due to thecentrifugal expansion of the grommet spring I80, this in turn increasingthe clutch torque until a-point is soon reached at which no furtherslippage between the friction faces I88, I84, and the rotating surfacesI08, I21 in contact therewith will occur even under full throttle torqueof the engine. Rotation of the plate I82 during engagement of the clutchis, by

reason of the engagement of the teeth I85 and I36, accompanied byrotation of the member I31 ,normally occurs.

and the pulley face IIO connected therewith.

It will be evident that torque is transmitted through the. pulley hubI00, housing H1 and torque link springs II5 to also rotate the pulleyface III. As the clutch is engaged, then, the vehicle move forward andthe clutch remains engaged until, due to the closing of the throttle orincrease in resistance to motion of the vehicle, the engine speed dropsbelow the speed at which the clutch initially locked in. When the speeddrops below this value, the clutch again slips.

If the engine is slowed down due to increased resistance to motion ofthe vehicle, as in climbing a hill or pulling a heavy load, the clutchwill slip under full engine torque, transmitting this torque to the restof the transmission and holding the engine speed down to a speedslightly below the one at which locking in of the clutch If the increasein resistance to travel be suflicient to completely stop the vehicle,the clutch will continue to slip under full engine torque, but it willbe impossible to stall the engine. If, however, the engine speed be intentionally reduced by closing the throttle, the clutch will disengageas the engine speed drops back through the engaging range into thenormal idling range and the engine will then idle freely. The enginespeed at which the clutch starts to engage as well as that at which itfinally locks in for any particular engine torque may be readilypredetermined by proper balance of the weight of the grommet spring I30,the initial tension of the spring, and the shape of the ramp I25.Individual or combined variation of these factors permitspredetermination of engagin and locking-in speeds over an almostunlimited range.

It might appear that wearing of the friction faces I33 and I 34 wouldcause an increase in the radius of the grommet spring I30 at which itproduces engagement of the clutch andthat the speed at which clutchengagement takes place would, therefore, be altered as wearing of thefriction faces occurs. But, since the'centrifugal force on the grommetspring increases directly in proportion to the radius of the grommetspring and the resisting force of' the spring also increases as afunction of the increase in radius, the outward movement of the springresulting in engagement of the clutch may, by proper proportioning ofthe mass and spring tension of the grommet spring in combination withproper shaping of the inclined face of the ramp I25, be. made to dependonly on the speed of rotation of the grommet spring. And since thecentrifugal force varies as the square of the speed of rotation, thespeed at which the centrifugal force overcomes the tension of thegrommet spring may be fixed with considerable accuracy. By properproportioning of the cooperating elements, then, the speed at which theclutch engages may be predetermined almost independ ently of relativeaxial positions of the elements for low speeds of the vehicle and beingdecreased as the vehicle speed increases. H The counterand independentof wear of the friction faces 1 shaft unit 46 is mounted on thecountershaft 48 which is supported in the bearings retained in the wheelhousing 40, and is restrained against motion along its own axis by a nutI50 bearing against the sprocket 5I at one end of the wheel housing andby a snap ring I5I, and a shroud I52 cooperating with a groove in thecountershaft at the other end of the wheel housing. On the end of thecountershaft 40 is mounted a pulley face and housing member I53, 9. discI54, a hub I55, and a sleeve I56, all welded into one unit. The hub I'is fitted to the countershaft." and is rotatively connected thereto bya key I51 which is positioned in a diametric slot in the countershaft 46and engages diametrically opposed keyways I50 in the hub I55. A snapring I cooperating with a groove in the countershaft 48 restrains thehub I55 from outward axial movement. For the purpose of compensating forbelt wear, as hereinafter described, a washer I49 is positionedsurrounding the shaft 48 and is limited in its rightward travel byabutment against the end of the key I51. The-rightward travel of the keyI51 in-turn is determined by the adjustment of a screw I 59 in threadedengagement with the shaft 48 and bearing against the key An axiallymovable inclined pulley face I6I is opposed to the pulley face I53 so asto cooperate therewithin providing inclined contact surfaces for thebelt ;41, and is piloted on the sleeve I56 by the inner tubular portionof an annular ramp I62 which is attached to the pulley face I6I bybending over the end portion I63 thereof. A cylindrical cage I64 ispiloted on the countershaft 48 adjacent the snap ring I5I and comprisesa series of circumferentially spaced fingers I65 extending throughcircumferentially spaced apertures I66 in the pulley face I6I andapertures I61 in the pulley face I53. The inwardly bent ends of fingersI65 are projected over a snap ring I68 surrounding the cylindricalhousing portion .of the pulley face I53, and are clamped. so as toattach the cage I64 to the pulley face I 53, by a closed clamping ringI10 which is sprung over and seated in the outwardly turned ends offingers I65. Between the fingers I 65 the interrupted cylindricaledge ofthe cage I64 is bent inwardly with a V-shape at suitable angles toprovide a series of aligned pairs of fulcrum edges I1I. U-shaped shoesI12 of suitable abrasionresistant metal are slipped over the fulcrumedges I1I. Pivoted about the fulcrum edges I1I are a plurality ofequalizer arms I13, preferably three in number and equally spaced aroundthe cageI 64, which are grooved at I14 to provide bearing grooves forthe fulcrum edges, and apertured at I15 to permit a finger I 65 of thecage to pass through. The curved outermost ends of these arms engage theback side of the pulley face I6I and are restrained againstcircumferential and against the frusto-conical end of a member I80 whichis slidably mounted on the countershaft 40. Hardened steel rings I8I arepressed into the 2,260,798 member in to provide bearing surfaces in eontact withvthe countershaft. The member III is urged in the direction ofthe equalizer arms I13 by resilient means, preferably comprising twocompression springs I82 and Iii-of different pitch diameters positionedin the space surrounding the cylindrical portion ofmember Ill and withinthe sleeve I56, and bearing at one end against the member I" and -attheother end' against a washer I84 which abuts diametricallyopposedadjusting screws I85 and Ilithreaded through the hub I55. By means ofthe adjusting screws I85 and I the compression of the'springs Ill andIllmaybechanged.

' moved evenly in an axial direction. The force against the fulcrumedges I'II holds the cage Ifl against the shroud I52 and the snap ringII, so that the cage is'flxed'in position relative to the pulley faceI53. The reaction of the springs. II? and I83 against the washer I" andthe screws I85 and I88 holds the hub I55 firmly in placeagainstthesnapringiill. v a

Within the housing portion of the pulley face member I53 is situated anannular ramp I81 which is loosely piloted at its central hole on thesleeve I56 and more snugly piloted at its periphery'by the shoulderI8l'of the pulley face member I53. Between the ramp Ill .and the pulleyface I53 aimarcelspring I" is compressed so that it has-a slighttendency to move the ramp I81 toward the opposed ramp I82. Confined be-'tween the opposed rampsjlfl and I8! is a pinrality'of steel balls ISIwhich enga e the ramps I62 d I81 on either side. The ramps I5! and ISIvre so shaped that the axial separation therebetween diminishes withincreasing distance from the countershaft I, and so that'they never-'open far enough apart to permit the balls III to pass out ofconfinement between theramps. The

sowhichtheratio ofenginespeedtowheelspeed tendency of the springs I82and I" is to cause the pulley face IN to approach the pulley face:

I53, thus bringing the ramps I62 and Ill nearer together and reducingthe diameter of the circleof'balls I9I.. The balls Illareperferablyofsuch diameter and in such number that when the unit 46 isnot in rotation the balls lie inIanannular ring closely around thesleeve III with each ball lightly pressed against the adjacent balls bythe tendency of the, two ramps to approach one another. Rotation oftheunit causes'the balls in to fly-outwardly the ramps .Ii2

and Ill, forcing the. rampiil, and with it the pulley face IBI, awayfrom the pulley face-I51 to a point where the increased force of I82 andI83 is sufficient to balance the centrifugal force on the balls. I!I."Whe n the countersbaft 48 is rotating,.then, the position'of-the-pulleyface IOI relative to pulley face- Ill isdeterminedby the centrifugalforce on the balls III which in turn is a measure of theispeed ofrotation of the I countershaft, or the speed of the-vehicle. The' parts-I to IUI form a driven pulley for the V-belt transmission which isgenerally designated by the numeral 46;.

The operation of as of the sprin s thecountershaft m in in; the positionof 5 ment of the-screws I85 and I, they preferably exert sufficientforce in their extended position 'tourgethepulleyface Iiitowardthepulley face I53 wlthagreaterforcethanthatwlthwhichthepulleyface III ism'gedtowardthepulleyfacelllbythespringslllandlliwhenintheir position. Therefore, when thevehiclcisinslowmotionandtheunitsfl and 46 are rotating, the pulley faceIOI will be moved to the closest permissible position relative to thepulley face I53,being iimitedbyabutmcntofthe inner-ends of the arms I'llwith the cage I, or.

'bythebelt ll comingtothepositionofminimal pitch diameter on the unit45. The belt llwill beforcedtonearflieouterpermheryofthepulley 2o facesI53 and ICI, causingit at thesametimeto 'move inwardly between thepulley faces III and III of unit 45 to occupy a position closetothepulley huh I, and forcing thepulley face III away from the pulleyfaceIII againstthe force Ill-and I18. Under these circumstances the that is,it is in a condition wherein-it provides the greatest ratio betweenengine speed and countershaft speed, orbetweencngincspeed andwheelauspeed. 7

If the throttle of engine II be-opened and the vehicle started forwardby engagement;of theclutch in the manner-previously described, the

vehicle willmove forward in this low gear posi- '-'1.;tion.' As thewheel speed increases, increase in the countershaft 48 will rotationalvelocity of subject the balls "I to centrifugal force which will causethem to-move outward against-the r ramps I62 and I8! and move the pulleydeface IiI away from the pulley face I53 against the forcefbf thesprings I82 and I83, as previously described. This will permit the beltH to move to a lower pitch diameterpn the unit 45, to which tion itwillbe forced by reason of the belt 45 moving to a larger pitch"diameter on the clutch and pulley unit 45' through action of the springsI22 and Iainurgingthepulleyface III toward the pulley face III. Inthiscondition the parts may occupypositlons as illustrated inFig- 3,in

hasbeenreducedfromthatcorrespondingtothe -lowgearcondition. f

.Btillfurtherincreascinwheelspeedwillresult in further increase incentrifugal force on the balls IOI', with resultant increase of theaxial forcetendingtoseparatethepulleyfacesofthe countershaft unit It.This permits the belt ll 'to be brought to a smaller pitch diameter onthe unit l5 and to'alargerpitclidiamei'eronthe.

unit ll, thus still further reducing the effective transmission ratio.When the wheel speed becanessufiiciently great,thepulleyface Iii willbedisplacedtothe posiidon of greatestpermissible separation in whichthemember Ill abuts the washer Ill and the belt 4'! lies adjacent, thefingers I orumit ll and close to the periphery of pulley faces II. andIII ofunit 45, the trans mission then being in the condition providingthe smallest permissible ratio of engine speed to wheel speed, that is,in high gear" condition.

Itis evident that when the vehicle slows down. -relative motion of thevarimiswts will occur in the reverse direction and. when the vehiclecomes toa standstilLthebelt 41 will againbe permissible pitchtransmission is'in "low gear";

diameter on the countershaft unit and the balls I9I will again beretracted to their smallest pitch circle. It will also be apparent thatthe speed at which the centrifugal force on the balls I BI firstnvercomes the resultant spring force and produces shifting of the speedratio of the trans-* mission and the speed at which the transmissionfinally reaches the high gear condition may be adjusted by moving thescrews I85 and I88 inwardly to increase the initial load upon thesprings I82 and I83, for outwardly to-reduce this initial tension. Thetransmission may thus be adjusted as desired to various road, load anddriving conditions, and by proper proportioning of the parts, almost anytype of variation of the eflective transmission ratio as a function ofvehicle speed may be obtained.

While the foregoing description of the operation of the transmissionexplains the manner in which it changes the transmission ratio inresponse to vehicle speed, the transmission is preferably also adaptedto vary the transmission ratio as the engine torque changes, in suchmanner as to render the overall performance of the'transmission muchmore suitable for propulsion of motor vehicles than if ratio change weredetermined solely by vehicle speed. The variation of I transmissionratio with engine torque is principally a result of the positionsassumed by the belt 41 relative to the pulleys of the units 45 and 45when torque is being transmitted.

The result of the above operation is that the transmission ratio of theV-belt transmission changes automatically in inverse proportion to, andas a result of, changes in vehicle speed. When the vehicle is at rest,the transmission is in low gear. That is, the engine can run at arelatively high speed with the wheel 42 running at a relatively lowspeed. As the vehicle accelerates to higher speeds there is acorresponding change in the transmission ratio and the vehicleautomatically goes into high" gear. This change to and from low gear toand from high gear is entirely automatic and is entirely dependent onvehicle speed. The transmission is diagrammatically shown in lowgear-inFig. l2 and in high gear in Fig. 13.

In the diagrammatic illustration of Fig. 11, the vehicle wheel 42 isrepresented as resting on the ground 49 and is driven from thecountershaft unit 48 by the chain 53. The belt 41 connects the clutchand pulley unit 45 with the countershaft unit 46. The direction ofrotation is indicated by the arrow. In this view, the belt -41 isrepresented in an intermediate position about one-third the way from theposition of minimal pitch diameter on unit 45, represented in Fig. 12,to the position of maximal pitch diameter on unit 45, represented inFig. 13. Preferably the springs I22 and I23 in the unit 45, and thesprings I82 and I83 in the unit 46 are so proportioned and adjusted thatthey balance one another in their eflect upon the transmission when thebelt pulley of unit 45. At the same time, the relative slack in theright side of the belt will permit this portion to creep to a largerpitch diameter on the countershaft unit 48. Depending upon .the balanceof forces involved, the degree to which the belt leaves the normalposition of Fig. 11 may vary overa wide range. One balance of forceswhich gives very desirable results in the type of vehicle underconsideration is that in which movement of the vehicle at low-speedthrough a distance of a few feet under full engine torque or clutchslipping torque will cause a shift of the belt into the position shownin Fig. 12,

' .pulley exert little or no axial force. Since the transmission underthese conditions would be expected to assume the position of Fig. 11,which is determined solely by balance of opposed spring forces, theadditional and very substantial increase in overall reduction gained bythe creeping of the belt into the position of Fig. 12 gives the vehiclegreatly improved hill climbing characteristics.

' If the vehicle is at rest with the transmission in the balancedposition of Fig. 11 and the throttle is slowly opened and the vehiclegradually' I accelerated and brought up to speed, the creepisapproximately in the position represented in Fig. 11, and the vehicle isat rest or travelling at low speed, in such manner as to make this beltposition one of equilibrium. In Fig. 11, if torque is being exerted bythe engine in the direction indicatedby the arrow, the belt 41 will beunder tension on the'left side, as shown, and will be relatively slackon the right side and may even loop outward as indicated by the dottedlines. With this belt condition, as rotation progresses, the taut sideof the belt will tend to creep to a smaller pitch diameter where itfeeds into the ing tendency Just described will be largely minimizedsince the belt tension will be low and the forces tending to causecreeping will be proportionally low. In this case the vehicle will startforward in what may be termed an intermediate ratio and as road speedincreases and the centrifugal forces on the balls in the countershaftunit 48 result in axial force on the movable pulley face of'this unit,the transmission will shift into the position shown in Fig. 13. If,however, from a static position, as in Fig. 11, the vehicle is rapidlyaccelerated by full opening of the throttle, the relatively high belttension will result in rapid creep into the position of Fig. 12 in thefirst few feet of forward movement, and even at low road speed theengine may rotate at such a speed that it delivers its maximal poweroutput.

This permits most rapid acceleration for any pare ticular engine andweight of vehicle. 'As soon as the engine speed reaches a peak value,the increase 'in wheel speed which corresponds to this increase inengine speed creates such centrifugal force on the balls of thecountershaft unit 48 that gradual shifting of the transmission ratiooccurs. the shifting of ratio continuing with increase of wheel speeduntil the transmission is again in the position shown in Fig. 13. Itwill thus be seen that for hill climbing or maximal acceleration thetransmission will automatically assume the lowest possible gear (highestratio of engine speed to wheel speed) at low wheel speed and will permitutilization of full engine power at these speeds. If, however,conditions make it unnecessary or undesirable to accelerate the vehicleas rapidly as possible, it may be accelerated more gradually under lowerengine torque and without the necessity of such high engine speed forany particular wheel speed.

Under normal traffic conditions, when the vehicle comes gradually to astop, the transmission will return from the high gear position of Fig.'13 to'the balanced position of Fig. 11, starting of the vehicle thetransmission may either rapidly drop into low gear position and *andupon van sponse to torque conditions independent orwheel pulley facestogether, and upon the force iconvaried-overawlde rangetoincreaseor-2,200,? I q orvarythecharacteroftheresponsetotorque.

bringingthevehicleto astopwiththe throttle 10 p v penedusingthebrakeifram. w stop the vehicle. .When this is done thetransbe subject toaforward driving torque while'the vehicle is and will shift into theextreme low position in the same manl5 ner it would upon encountering Wof tractive resistance. It is clear'that if the vehicle is operating athigh wheel-speed with the belt 41 in a position ofmaximal pitchdiameteronthepulley ofthe 20 unit", as shown in'I'ig. 13, and thedirection of applied torque is as indicated by the arrow, a slack loopwill under these conditions appear on the right side of the belt. Theamount of slackwhichappearsinthisloopdependsuponss belt tension orengine torque. Under light en-' gine loads, little slack will appear,but under conditions'of high torque the belt will. tend to creep to asomewhat smaller diameter upon the pulley of unit and feed more slackinto the loop I. 30,

Thus, when the vehicle is operating in the high speed range at lightengine load and torque, the

ratio of engine speed to wheel-speed will be aminimum, but, if enginetorque is increased for the purpose of acceleration or hill climbing,reso duction of effective pitch diameter on the pulley of the unit willcause a change in the transmission ratio to' increase the mechanicaladvantage of the engine.

Another manner in which the creeping tendency of thebeltisutilized,inthis caseto improve the easewith which the vehicle maybe started by pushing it forward, is shown in Fig. 14. This figurepresents the condition which exists when the vehicle has previously cometo rest with the 45 pulleys and belt in the balanced position of Fig.11, and is then being pushed forward with the engine at rest. Appliedtorque is as indicated .by the-arrow and the right side of the belt isnow under tension and the left side of the belt 50 exhibits a certainamount of slack. As soon as the engine starts to rotate, 'the creepingtendency willcausethebelttoseekasmallerpitchcircle on-the pulleyo! thecountershaft unit II and a larger pitch-circle onthe pulley of the unitit, as -thusincreaaing themechanical anddiminishingtheforcenccessaryto'pushthevehicle'ahead..Ordinarilytheenginewillstart-in or four turns before the eifect'ofcreep has caused" much change in ratio, but if for any 0.re'ascn'the'engine fails to readily start, the decreisein ratio ofengine speed to wheel speed" 'ca'med hyeontinuing creep,'with resultantdein effort required to push the vehicle, is t we n -'-I vantage. I

in whicmbelt, creep permits adchangeofonratioin respeed, depends uponthe face angles of the polleys and belt, the particular pitch diameterat 7 which the belt is operated on each pulley, the

load exerted by the springs tending to force the stante of thesesprings.These factors maybe when adapted to one specific application.

Intheofmy'inventlon illustratedherein,afin'thercontrole1ementhasbeenintro-' duced in thc'constl'uctionto accentuate thecreepingtmdencyofthebeltnndercertaincondiflonsofoperatlonandtoreduceitundercertainother conditions, thus further improving vehicle performance. Referenceto Figs. 3, 7, andii'wlllshowthatthetorquelinkspringsllioftheunitllarenormallyinstalled areunder compressionwhen driving torque,ap- I pliedtothehousingll'l bythepulley-hub I,'istransmittedthroughtheposts llIintothe springs Hi. It will beclear'that when the springs III are angularly disposed relative to theof rotation of the wit, the compressive force in the springs I underforward driving torque will have an axial component tending to movethepulley face .lll in an axialrdirection whichis dependent upon whetherthe springs ll! diverge at an angle to therleft ate the right from theplane of rotation. The parts of the unit II are so p p rtioned andpodtioned relative to one another that the springs III lie parallel tothe plane of rotation when the movable pulley face Ill occupiesaposition .twiththepositionofthebeltinrlg. 11.

When the pulley face III is moved tothe right from this position towardthe condition repre sented in Fig. 12, the axial component of the forceof springs III is such as-to move the movable face I'll still farther tothe right; while if the pulley face I is moved tothe left from thenormal position. the axial component of the forceofspringslliisinsuchadirectionastomove;

the pulley face still farther to the left.

Reconsideration now of the creeping of the beltat low speed and hightorque from the balanced position of Fig. 11 to the extreme low gearposition of Fig.12, will show that the increasing axial component of theforce of springs 5 as the pulley faces separate tends to augment the andto make the on shift-into extreme. low gear more rapidly'with increaseof torque. Simil'arof the creep ing tendency, which will exist underincrease of torque inthe high speed range, will show that theaxial'forceof the torque links III is opposed tothenormalcreepingtendencysothatthechange of on ratio under increaseof 'throttlewhentheonisinhighspeedpositionsisless'than it wouldbe'ii the torque were transmitted through astraight key and keyway orother device which is free of axial reactionas a functionof torque. zlt'will be evi-' 1 dent,then,thatunder1owspeedsand severe conditions of pulling.,tl1'elsmoreresponm ratio change to increase of tractive eifort and increase ofengine torque than sivein in the high range. In a vehicle where thepower is limited audit is important to obtain 'maximalhill climbingcharacteristics and maxitractive eflort at low the advantageofsuchantisobvious'.

Figs. 15 and 16 present curvesillustrating the performance of the 1 wofmyinvention In this applications, Johnson X301 iron Horse engine wasused. Curve III shows the manner in which thetorque of this enginevaries with engine speed, 1

and curve Ill shows the manner in which the engine horse power varieswith engine speed. It

will be noted that the enginerhas a maximal torque of about 29pounds-inches at 1'100 R.P.'M.,

and a maximal. horsepowerof 1.0 at about 2500 R. P. M. ,Curve 202 showsthe manner in which the ratio of engine speed to wheel speed in theparticular application under consideration varies in response only tovehicle speed. This curve starts from an intermediate ratio of 8.5 to 1,corresponding to the balanced position of the V-belt on the pulleys withthe vehicle stationary, as shown in Fig. 11, and remains at this ratiountil the vehicle speed is about miles per hour, beyond which the ratiogradually decreases to a value of about 2.75 to 1 at 30 miles per hour.The curve 202 then presents what might be termed the no load change ofratio which would be obtained if the vehicle could be accelerated from astanding position to its maximum speed without actual application ofdriving torque or building up of tension on the V-belt.

Curve 203 shows the manner in which the change in transmission ratiotakes place under full engine torque, assuming that the vehicle startswith the transmission in the extreme low gear position. Under theseconditions the transmission ratio will start at about 12 to 1 and remainat this value until the vehicle attains a speed of about 5 miles perhour. When this speed is reached, the centrifugal forces acting upon theunit 46 will induce a change of transmission ratio, and if the vehicleproceeds under full throttle, the change of ratio will be complete atabout 30 miles per hour and the final high speed ratio will be about 3to 1. The displacement of the curve 203 from the curve 202 is areflection of the change in transmission ratio produced by thepreviously discussed creeping-tendency of the belt.

. 12 miles per hour, the change of transmission ratio continuesaccording to such a function of increasing vehicle speed that the enginespeed remains substantially constant at 2500 R. P. M. and

. Curve 204 shows the transmission curve cor- I responding to a startunder full throttle from the intermediate balanced ratio positionillustrated in Fig. 11. It will be noted that the ratio of engine speedto wheel speed, increases rapidly while the vehicle is being acceleratedto 5 miles per hour. beyond which if acceleration is continued underfull throttle operation, the ratio change, of course, follows that ofcurve 203.

It will be evident that operation of the vehicle with partial throttleopenings would be indicated by curves lying between curves 202 and 203,and that a typical curve for ratio change under moderate accelerationmight be one such as curve 205.

Curve 208 represents the variation of engine speed with vehiclespeed'under conditions corresponding to the maximal acceleration curve203, and may be understood from the following description of the actiontaking place. The engine under consideration has a normal idling rangeof from 800 to 1050 R. P. M. and the clutch is adjusted to startengagement at an engine speed of approximately 1100 R. P. M. Followingengagement of the clutch, the engine speed stays at about this valueuntil the vehicle speedhas reached about 3 miles per 'hour. During thisperiod the clutch at first slips considerably, but as the speed of thevehicle approaches 3 miles per hour, the slipping diminishes and slightincrease in vehicle speed above 3 miles per hour then permits the engineto accelerate with almost no slip, the clutch finally locking-in atabout 1400 R. P. M. and 4 miles per hour. From 4 miles per hour to aspeed of about 8 miles per hour, engine speed varies almost directly asvehicle speed. It will be noted that this portion of the curve 206 ispractically a straight line and that in the corresponding portion ofcurve 203 there is very little change in ratio. When vehicle speedreaches 8 or 9 miles per hour, relatively rapid change of 'ratio occurswith the result that, although the vehicle accelerates rapidly to a,much greater full engine power is available for acceleration up to thenormal maximum of 30 miles per hour. With the particular adjustment oftransmission and the particular chain and sprocket combination employedin the application under consideration, the transmission completes itsshift into the high gear position at about 30 miles per hour, and fromthat point on any increase in vehicle speed leaves the ratio unchangedIncrease in vehicle speed above 30 miles per hour therefore necessitatesincrease in engine speed, as indicated by the oblique upper portion ofthe curve 206, but in a small vehicle of the size and weight propelledby an engine such as that in the application under consideration, suchspeeds are normally not attainable on the'level, and this possibleincrease of engine speed above the point at which the horsepower curvepeaks is obtainable only when running down hill.

Curve 201 represents the variation of engine speed with vehicle speedunder the no load condition corresponding to the curve 202. This curveshows the same general response of engine speed to change of vehiclespeed, but it will benoted that for any vehicle speed, the correspondingspeed of the engine under no load condition is appreciably lower. Thispermits a great increase in life of the engine and reduction ofmaintenance costs if the operator chooses to ,use only partial throttleopening during acceleration.

By appropriate change of the curvatures of the ball ramp in thecountershaft unit 46, it is possible, if desired, to delay the point atwhich change of ratio from normal extreme low gear position commencesuntil the peak of the power curve is reached at-2500 R. P. M., and thento introduce'a rapid change of ratio to hold the engine speed at thispeak value at higher road speeds. The engine speed versus vehicle speedcurve forsuch a construction is indicated by the dashed curve 208 whereit diverges from the curve 206.

' If it be considered that the curve 206 re resents the performancewhich would be obtained with the springs I82 and I83 of the countershaftunit 40 in the position of intermediate adjustment aflorded by screwingthe screws I85 and I06 inward a distance equal to half their threadedlength, then retracting these screws to their'extreme rightward positionas seen in Fig. 3 would result in an engine speed versus vehicle speedcurve as indicated by the line 209, the lower and upper portions ofwhich merge into the curve 201. Conversely, maximal initial compressionof the springs achieved by screwing the adlusting screws I85 and I06inward the full threaded length, would result in an engine speed versusvehicle speed curve as suggested by the curve 2I0. It is evident thatthis adjustment, which is under the control of the operator, permits theoperator of the machine to adjust the eilective transmission ratio tosuit his individual needs. A lightweight rider, for instance,

' might use the adjustment indicated by curve 209,

while a heavyweight rider might prefer the "adjustment indicated by thecurve 2I0.

In vehicles in rental service or in messenger and delivery service wherethe operators might be inclined to ride the vehicles'more or less contleopenings, excessive strain on the engine may be avoided by substitutingfor the ball ramps I62 and I8! of the countershaft unit 48, rampshaving. less curvature. If the ramps are modifled in this manner, thecurve of engine speed versus vehicle speed at full throttle opening maybe modiiled in the manner of curve 2. It will be noted that a curve of.this sort permits use of peak engine power for maximal performance bothin acceleration and in hill climbing at low or moderate vehicle speeds,but when the vehicle speed reaches approximately 20 miles per hour, theratio change of the transmission becomes progressively greater so thatthe engine actually slows down with increase of vehicle speed. Thismeans that the engine is held at a tion, gradually diminishes intransverse width due to compression and abrasion by the surfaces of thepulleys and to other factors causing wear,

and special provision is made to permit adjust-' the extreme low gearposition in which it has the minimal pitch diameter on unit 45, thewidth of the new belt is such as to prevent the pulley face I6I of unit46 from coming into the extreme rightward or closed positioncharacteristic of the low gear condition with a used belt. In thisposition of the pulley face I5I, the ball ramps I52 and I8! may not bepressed together suilicientiy to retract the balls I9I into a circle ofminimal speed below the one at which it delivers maximal power, and thenormal high speed of the'vehicle on a level road is somewhat reduced.This slight reduction in engine output and substangreat as it would beif greater engine torque could be applied at any particular ratio. If itis important that maximal starting performance of the vehicle beattainable, the tension of the grommet spring I30 in the unit 45 may beincreased or the weight of the spring may be reduced by removal of aportion of the filler spring I3I, by substitution of a filler spring oflighter weight or by total elimination of the filler spring, and theclutch will accordingly not begin to engage until a relatively highengine speed has been attained. If the clutch be modifled 'in thismanner, the low speed portion of the engine speed versus vehicle speedcurve 209:

will be modified as suggested by the curve 2I2.

It is understood that the performance curves discussed above arepeculiar to one particular type of engine with its individual horsepowerand torque characteristics. In a group of engines of presumablyidentical characteristics,

some variation in performance at different speeds will often orusuallyappear. It is obvious that the individual adjustment made possible bythe construction of the transmission of my invention permits substantialmodification of transmission characteristics to obtain the best possibleperformance or the most desirable performance from any particularengine. It should a 0..be noted that the overall response of thetransmission to tractive effort, engine torque, and vehicle.speedismodifled by the reduction ratio diameter in which each balltouches. the adjacent ones. Since, under these conditions, the balls I9Imight be loosebetween the ramps I52'and I81 and have a tendency torattle when the speed of rotation is so low that centrifugal force isinsufilcient to overcome the force of gravity on the balls, the marcelspring I99, interposed between the ramp I91 and the housing portion ofthe pulley face I53 is depended upon to" force the ramp I81 toward theramp I92 and in this manner take up any slack between the balls and theramp. The halls I9I are thus properly centralized on the minimal pitchcircle until such time as centrifugal force enables themrto firstcompress the marcel spring I99 and thenseparate the pulley faces bydirect pressure upon the ramps.

In the high gear position, the belt 41 has its minimal pitch diameter onthe unit 46 and the separation of the pulley faces I5I and 153 islimited by abutment of the member I 99 against the washer I49, theextreme rightward position of which is in turn determined by theadJu'stmentL of the screw I59. When a new beltis used, it is necessaryto retract the screw I59 to permit the washer I49 to assume a positionas far to the right in Fig. 3 as possible in order to allow the pulleyfaces to separate a distance sufiicient to accommodate the new belt inthe position of minimal pitch diameter. As the belt diminishes.

in width due to wear, it may seat more deeply in the pulley of unit 46and eventually bear against the fingers I65, and for this reason thelingers I have edges so formed that the belt may run against themwithout damage. If the power transmitted by the belt is relativelylight, it may be transferred from the inner face of the belt 41 to thefingers I65 without abnormal slip, even fingers may be insufficient totransmit this power of the sprocket and chain employed and by'the Itotal load and. force constants of the springs I22 and I29 in the unit45. Change of sprocket ratio will have the general effect of increasingorre'ducing the miles per hour scale of the charts of Figs. 15 and. 16..Change of the total load or force constants of'the springs I22 and I29is equivalent to change of thetotai load and force constants of thesprings I92 and .I" inthe unit. In the use 01' my transmission, theV-belt,

without undue slip, and ii may become necessary to restore the sidecontact ofthe pulley faces against the belt. This is done by turning thescrew I99 inward so" that it moves the key I51 leftward in Fig. 3 andestablishes a new limiting position for rightward travel of the memberI". v This adjustment may be easily made by theoperator of the vehiclewhenever'the engine gives audible evidence ofv racing when the machinetravellmr at high speed.

In Fig. 1': I Show alternative m of the created in the engine intake. Inthis case the countershaft unit 46 is mounted on a countershaft 228which, except for the end portion upon which the unit 48 is mounted, issimilar to the countershaft 48 in the apparatus previously described,and is similarly connected with the other associated parts. -In the formof the unit shown in Fig. 17 the hub 22I takes the place of the hub I55in the previously described unit and is connected for rotation with thecountershaft.

228 by means of a key 222. The hub 22I is retained on the countershaftby snap ring I68 engaging a groove on the countershaft. The springs I82and I83 act at one end on the member I88 and at the other end on awasher 223 which abuts the adjusting screws I85 and I86 and is turnedinwardly to pilot on the hub 22I.

Surrounding the spring I83 and clamped between the spring I83 and theabutting surfaces at either end thereof, is a cylindrical sheet 224 offlexible material, such as rubber, composition, or fabric, which formswith the supporting spring I83 an air-tight bellows providing a chamberwithin.

The countershaft 228 has an axial bore 225 extending part way from itsouter end, and communicating with the bore 225 and the chamber withinthe bellows 224 is a passage 226. A fitting 221 has a cylindricalportion 228 fitting the bore 225 so as to permit the countershaft 228 torotate while the fitting 221 remains stationary. A

passage 238 connects with the bore 225 at one end and at the other endwith suitable conduit means leading tothe intake of the engine II insuch manner that a vacuum is produced within the bellows 224 byoperation of the engine 4|. In order to permit compensation for wearingof the belt, the movable pulley face is made in two parts, the innerportion 23I being attached to the ramp I62 for piloting on the sleeveI56 in the same manner in which the movable pulley face I6I wasconnected thereto in the form of the unit previously described. Theouter inclined portion 232 which is adapted to contact the belt 41 isattached to the inner portion 23I by three or more screws 233 which arethreaded through the portion 23I and are riveted to the portion 232 asat 234 in such manner that the screws 233 may turn within the portion232. It will be clear that with this construction the pulley face 232may, for any position of the portion 23I, be moved toward or away fromthe pulley face I53 as may be necessary to compensate for differentwidths of belt. The remaining parts of the unit 46 may be constructed aspreviously described in connection with the unit illustrated in Fig. 3.

The operation of the unit as illustrated in Fig.

17 is similar to the operation of the previously described unit of Fig.3, except that in the unit of Fig. 17, the position of the movablepulley face 232 is changed as the degree of vacuum produced by theengine changes. The vacuum within the bellows 224 tends to counteractthe compressive force of the springs I82 and I83, so that the greaterthe degree of vacuum, the more the pulley face 232 will be moved awayfrom the opposing pulley face I53 and the more the transmission will beshifted toward the high gear condition. The degree of vacuum produced bythe engine is dependent upon the throttle opening and the speed of theengine, increasing with the speed, and decreasing as the throttle isopened. The vacuum produced within the bellows 224 may be furthermodified by a valve in the conduit connecting passage 238 with theengine intake.

It will be evident that many different effects may be secured byadjustment of the screws I and I86 to vary the compression of thesprings I82 and I83, and by varying the adjustment of the vacuum controlvalve. One desirable condition is that in which the belt 41 occupies anintermediate position on the pulley of unit 45 when the engine H isidling. Under these circumstances the compressive force of the springsI82 and I83 is partially balanced by the vacuum within the bellows 224,and when the engine throttle is opened to accelerate the vehicle, thedegree of vacuum within the bellows 224 is lessened, permitting thesprings I82 and I83 to act on the equalizer arms I13 to move the pulleyface 232 closer to the opposing pulley face I" and quickly bring thetransmission into low gear position. As the speed of the vehicle buildsup and less throttle opening is required, the degree of vacuum withinvthe bellows 224 will increase and assist the centrifugal action of theunit in bringing th emovable pulley face 232 to the extreme high gearposition.

In Fig. 18 is shown an alternative form of the clutch portion of theunit 45 in which the inclined tooth mechanism for starting is eliminatedand the clutch is engaged for starting by the inward movement of thegrommet spring. which results when the unit comes to rest. In this formof the unit 45, a ramp 248 is attached to the housing I83 at I26, as inthe form of the apparatus previously described, and has substantiallythe same shape in its outward portion as the ramp I25 in the form of theunit shown in Fig. 3. The inner portion of the ramp 248, however,preferably extends inwardly substantially parallel to the plane ofrotation nearly to the member I31. A floating plate 24I, similar in itsouter portion to the floating plate I21 of the previously describedunit, is connected for rotation with the ramp 248 by the ears I28projecting through holes in the ramp 248. The inner portion of thefloating plate 2 is formed into a frusto-conical shape directed towardthe opposing ramp 248. The grommet spring I38 is similar to the springdescribed in connection with the unit of Fig. 3 except that it is madewith a fewer number of turns in the outerspring to permit it to retractinto a circle of smaller diameter.

evident that when the mechanism comes to rest, as is the case when theengine stops, the grommet spring I38 will retract inwardly and byengagement with the ramp 248 on one side and the floating plate 2 on theother side, will force the floating plate 24I leftward, resulting inengagement of the floating plate 2 with the friction surface I33, andengagement of the friction surface I34 with the housing I83. In thiscondition the engine H is connected through the clutch to the pulley ofthe unit 45 and if the vehicle is moved forward, the engine will berotated and will start. When the engine starts, the resultant increasein speed will cause the grommet spring I38 to expand under the influenceof, centrifugal force until it occupies the position shown in Fi 18. Inthis position the clutch is disengaged and the engine may idle freely.Further increase in engine speed will result in normal engagement. fordriving the vehicle in the'ma'nner set forth previously in connectionwith the apparatus of Fig. 3. Normal engagement and disengagement of theclutch under With the construction shown in Fig. 18, it is While notessential for the functioning of the mechanism, it is desirable toprovide a spring 242 for the purpose of centralizing the grommet springI30 when in the idling position so that it cannot rotate eccentricallyor out of balance, and thus prevent possible partial or intermittent anderratic clutch engagement. This spring 242 may take the form of a marcelspring bearing on the ramp 240 and threaded through various of the earsI28. This spring then urges the floating plate 2 rightward in suchmanner as to always maintain contact between the grommet spring I30 andthe ramp 240 at one side, and the floating plate 2 at the other side.

In the alternative forin of theunit 45 shown in Fig. 19, a flat floatingplate 245 parallel to the plane of rotation is employed on one side ofthe grommet spring I30 and a ramp 245 is positioned on the other side ofthe grommet spring and is so shaped as to approach the plate 245 oneither side of an intermediate diameter. A coil spring 241 hearing atone end on the housing I03 and at the other end on the floating plate245 assures contact of the grommet spring I30 with both the floatingplate 245 and the ramp 245 at all times. In this form of the unit asingle member 248 takes the place of the disc I32 and the member nestedthe grommet spring 252. Preferably welded to the inner edge of. the ramp25I. is another ramp 253 which approaches the floating plate 245 as itproceeds inwardly and has an ar I31, being connected at its outer endwith the friction faces I33 and I34, and at its inner end to the pulleyface IIO by means of the lugs I39. This construction eliminates thecoupling teeth I35 and I35 of the previously described construction, butis accompanied by the disadvantage that cuate outer portion within whichis adapted to be nested a grommet spring 254. Except for the fact thatno retracting spring for the floating plate 245 is required, theconstruction of the remainder of the unit is similarto that previouslydescribed in connection with Fig. '19. The parts of the mechanism areshown in the positions which they take when the engine is idling. Thegrommet spring .252 cooperates with the ramp.2 5l and the floating plate245 to effect clutch en-.-

gagement at speeds of the engine greater than idling speed in the samemanner as has previously been described in connection with the apparatusof Fig. 3. When the engine stops, the grommet spring 254 retractsinwardly to a smaller diameter and by reason of engagement with the ramp253 forces the floating plate 2'45 to the left, causing the clutch toengage, whereupon the engine may again be started by forward motion ofthe vehicle. When the engine starts, the grommet spring 254 will bethrown outward into the position shown in Fig. 20, resulting indisengagement 0f the clutch to permit free idling of the engine.Employment of two springs 252 and 253, instead of one, makes it easierto proportion the parts of the mechanism with minimal mechanicalcompromise.

While I have disclosed my transmission in con-' nection with athree-wheeled vehicle, it will be understood that the transmission maybe employed in the propulsion of a two-wheeled vehicle, which, forexample, may be of the general type disclosed in'the patent applicationof Howard B. Lewis, Bruce Burns, Austin E. Elmore, and Esley F.Salsbury, Serial No. 202,868, or in any other suitable form of vehicle.It will also be understood that various variations or modifications inas the member 240 'moves during engagement and disengagement of theclutch, the pulley face H0 is also required to move. To permit thelimited movement required of this pulley face, the hub I02 is reduced at250 to permit movement of the bushing I0I upon it.

The operation of the unit illustrated in Fig. 19 is similar to that ofthe previously described unit shown in Fig. 18. The parts are shown inthe position which they would take during idling of the engine. When theengine stops, the grommet spring I30 retracts inwardly and the curvedinner portion of the ramp 240 introduces an increased component of axialengaging force which is exerted against the floating plate 245, and inthis manner the clutch is engaged preparatory to restarting the engineby motion of the vehicle in design or construction of the parts oftheapparatus of my invention other than those disclosed herein may be madeby those skilledin the art without departing from the spirit and scopeof the appended claims.

The invention disclosed herein was disclosed in my application Serial253,557, flled 'January 30,

1939, entitled Motor vehicle and automatic' power transmission meanstherefore, of which this is a division.

from the idling condition, the grommet spring grommet springs areemployed to perform separately the functions of clutch engagement forengine starting and clutch engagement for movement of the vehicle. Aramp 25I is provided of the same general character as the ramp I25 inthe unit illustrated in Fig. 3- and is"attached to the housing I03 in asimilar manner. The ramp 25I has an arcuate' inner portion within whichis I claim as my invention:

1. In a vehicle the combination of an engine 'having a shaft; a drivingwheel; a variable speed reduction gear, said speed reduction gearcomprising'a driving shaft, a driven shaft, a driving pulley carried onthe driving shaft of said gear, a driven pulley carried on the drivenshaft of said gear, and a V-belt passing over said pulleys, theeifective diameter of which pulleys may be varied to vary the speedratio of said gear; mechanism through which the driven shaft of said earcan drive said driving wheel; a clutch adapted, when engaged, totransmit power from the shaft of said increase or reduce the ratio ofsaid gear as thespeed of said driving wheel is reduced or increased.

2. In a vehicle the combination of: an' engine having a shaft; a drivingwheel; a, variable speed reduction gear, said speed reduction gearcomprising a driving shaft, a. driven shaft, a driving pulley carried onthe driving shaft of said gear, a driven pulley carried on the drivenshaft of said gear, and a V-belt passing over said pulleys, theefiective diameter of which pulleys may be varied to vary the speedratio of said gear; mechanism through which the driven shaft of said earcan drive said driving wheel; a clutch adapted, when engaged, totransmit power from the shaft of said engine to the driving shaft ofsaid gear; centrifugally actuated means driven at all times at a speedproportional to the speed of said engine shaft; spring means forrendering said centrifugally actuated means inoperative at all speedsbelow a definite critical speed, said centrifugally actuated means beingadapted to cause said clutch to engage whenever said centrifugal meansare rotated above said critical speed; centrifugally actuated memberscarried by the driven shaft of said gear and, therefore, rotated at alltimes at a speed proportional to the speed of said driving wheel; andmechanism through which said centrifugally actuated members increase orreduce the ratio of said gear as the speed of said driving wheel isreduced or increased.

3. In a vehicle the combination of: an engine having a shaft; a drivingwheel; a variable speed reduction gear, said speed reduction gearcomprising a driving shaft, a driven shaft, a driving pulley carried onthe driving shaft of said gear, a driven pulley carried on the drivenshaft of said gear, and a V-belt passing over said pulleys, theeffective diameter of which pulleys may be varied to vary the speedratio of said gear; mechanism through which the driven shaft of saidgear can drive said driving wheel; a clutch adapted, when engaged, totransmit power from the shaft of said engine to the driving shaft ofsaid gear; centrifugally actuated members carried by the driven shaft ofsaid gear and, therefore, rotated at all times at a speed proportionalto the speed of said driving wheel; and mechanism through which saidcentrifugally actuated members vary the effective diameter of saiddriven pulley to decrease the speed ratio of said gear as the speed ofsaid driving wheel increases and increase the speed ratio of saiddriving wheel as the speed of said driving wheel decreases.

4. In a vehicle the combination of: an engine having a shaft; a drivingwheel; a variable speed reduction gear, said speed reduction gearcomprising a driven shaft, 9. driving shaft, a driving pulley carried onthe driving shaft of said gear, a driven pulley carried on the drivenshaft of said gear, and a V-belt passing over said pulleys, theeffective diameter of which pulleys may be varied to vary the speedratio of said gear; mechanism through which the driven shaft of saidgear can drive said driving wheel; a clutch adapted, when engaged, totransmit power from the shaft of said engine to the driving shaft ofsaid gear; centrifugally actuated means driven at all times at a speedproportional to the speed of said engine shaft; spring means forrendering said centrifugally actuated means inoperative at all speedsbelow a definite critical speed, said centrifugally actuated means beingadapted to cause said clutch to engage whenever said means are rotatedabove said critical speed; centrifugally actuated members carried by thedriven shaft of said gear and,-therefore, rotated at all times at aspeed proportional to the speed of said driving wheel; and mechanismthrough which said centrifugally actuated members decrease the speedratio of said gear as the speed of said driving wheel increases andincrease the speed ratio of said driving wheel as the speed of saiddriving wheel decreases.

5. A vehicle as defined in claim 1 in which the mechanism through whichthe driven shaft of the variable speed reduction gear can drive .thedriving wheel, comprises, a sprocket carried by the driven shaft of thevariable speed reduction gear, a sprocket drivingly associated with thedriving wheel, and a drive chain extending around said sprockets.

6. A vehicle as defined in claim 2 in which the mechanism through whichthe driven shaft of the variable speed reduction gear can'drive thedriving wheel, comprises, a sprocket carried by the driven shaft of thevariable speed reduction gear, a sprocket drivingly associated with thedriving wheel, and a drive chain extending around said sprocket.

' BRUCE BURNS.

